MapWindow 4 - Desktop Application : MapWindow Discussion Forum
Sorry if this is long, I'm just trying to be thorough :) I am having some difficulties positioning a series of GeoTIFF images properly in MapWindow GIS (which is a tool I just heard about, so I'm new to it). I have attached one of the Tiffs (Test_Tiff.zipx, not .zip) and some other
GeoTIFF Georeferencing Problems
Posted by: PlaneShaper ()
Date: March 18, 2011 03:03PM

Sorry if this is long, I'm just trying to be thorough :)

I am having some difficulties positioning a series of GeoTIFF images properly in MapWindow GIS (which is a tool I just heard about, so I'm new to it). I have attached one of the Tiffs (Test_Tiff.zipx, not .zip) and some other reference files if you'd like something to work with.

Basically, my problem is this. I have a series of about 800 Tiffs that are supposed to be positioned around Lubbock, TX, but instead, they wind up at crazy impossible coordinates (227,000 Lat, 3.71 million Lon).

I have two separate viewers that position them correctly on the surface of the earth, but they aren't as capable at manipulating the way the images look as MapWindow (and one of the two tools skews the images in relation to each other, even though they are positioned correctly in general).

Each image is 1001x1001 pixels, and contains actual projection information in metadata. They are coordinate mapped based on Eastings and Northings in Meters in UTM Zone 14N. The problem is I also have a series of Shapefiles that I need to overlay on these Tiffs, with coordinates in DD and DMS.

I just haven't been able to figure out how to match these files up correctly in MapWindow.

The first reference file (*.gtf, just open it in Notepad) is the header information pulled by listgeo:

Geotiff_Information:
   Version: 1
   Key_Revision: 1.0
   Tagged_Information:
      ModelTiepointTag (2,3):
         0                0                0                
         227000           3711000          0                
      ModelPixelScaleTag (1,3):
         1                1                0                
      End_Of_Tags.
   Keyed_Information:
      GTModelTypeGeoKey (Short,1): ModelTypeProjected
      GTRasterTypeGeoKey (Short,1): RasterPixelIsArea
      GTCitationGeoKey (Ascii,33): "UTM Zone 14, Northern Hemisphere"
      GeogCitationGeoKey (Ascii,7): "WGS 84"
      GeogAngularUnitsGeoKey (Short,1): Angular_Degree
      ProjectedCSTypeGeoKey (Short,1): PCS_WGS84_UTM_zone_14N
      ProjLinearUnitsGeoKey (Short,1): Linear_Meter
      End_Of_Keys.
   End_Of_Geotiff.

PCS = 32614 (name unknown)
Projection = 16014 ()
Projection Method: CT_TransverseMercator
   ProjNatOriginLatGeoKey: 0.000000 (  0d 0' 0.00"N)
   ProjNatOriginLongGeoKey: -99.000000 ( 99d 0' 0.00"W)
   ProjScaleAtNatOriginGeoKey: 0.999600
   ProjFalseEastingGeoKey: 500000.000000 m
   ProjFalseNorthingGeoKey: 0.000000 m
GCS: 4326/WGS 84
Datum: 6326/World Geodetic System 1984
Ellipsoid: 7030/WGS 84 (6378137.00,6356752.31)
Prime Meridian: 8901/Greenwich (0.000000/  0d 0' 0.00"E)
Projection Linear Units: 9001/metre (1.000000m)

Corner Coordinates:
Upper Left    (  227000.000, 3711000.000)
Lower Left    (  227000.000, 3709999.000)
Upper Right   (  228001.000, 3711000.000)
Lower Right   (  228001.000, 3709999.000)
Center        (  227500.500, 3710499.500)

The big problem seems to lie in the Corner Coords. Whenever I open any of these Tiff and then try to lay down a Shapefile with DD or DMS coords into the window as well, MapWindow uses these Corner Coords as Lat/Long values for the Tiffs, and places them in non-existant parts of the Earth.

The next file (*.geom, also open it in Notepad) is calculated metadata information by one of the two other viewers I'm using.

image0.band0.max_value:  65535.000000000000000
image0.band0.min_value:  1.000000000000000
image0.band0.null_value:  0.000000000000000
image0.central_meridian:  -99.000000000000000
image0.datum:  WGE
image0.elevation_lookup_flag:  1
image0.ellipse_code:  WE
image0.ellipse_name:  WGS 84
image0.entry:  0
image0.false_easting_northing:  ( 500000.000000000000000, 0.000000000000000 )
image0.false_easting_northing_units:  meters
image0.hemisphere:  N
image0.ll_lat:  33.494723469820684
image0.ll_lon:  -101.938415246642780
image0.lr_lat:  33.494978169349594
image0.lr_lon:  -101.927664074791850
image0.lr_x:  1000.000000000000000
image0.lr_y:  1000.000000000000000
image0.major_axis:  6378137.000000000000000
image0.minor_axis:  6356752.314199999900000
image0.number_input_bands:  1
image0.number_lines:  1001.000000000000000
image0.number_output_bands:  1
image0.number_samples:  1001.000000000000000
image0.origin_latitude:  0.000000000000000
image0.pixel_scale_units:  meters
image0.pixel_scale_xy:  ( 1.000000000000000, 1.000000000000000 )
image0.radiometry:  16-bit unsigned
image0.tie_point_units:  meters
image0.tie_point_xy:  ( 227000.500000000000000, 3710999.500000000000000 )
image0.type:  ossimUtmProjection
image0.ul_lat:  33.503731224142932
image0.ul_lon:  -101.938719863520430
image0.ul_x:  0.000000000000000
image0.ul_y:  0.000000000000000
image0.ur_lat:  33.503986010194602
image0.ur_lon:  -101.927967581017510
image0.zone:  14
number_entries:  1

As you can see, this program correctly converts the Corner Coords from the Tiff into appropriate DD coords. The Tiffs are placed in the correct positions relative to the earth and it doesn't seem to be a big issue.

The last reference file (*.zip, not .zipx) is just a piece of one of the shapefiles that should overlay this image (a bit NW of center).

I've tried a couple things, but being unfamiliar with the tool, I don't know if anything I've done would have really been of value. One thing I did attempt that I think is worth noting is I did try using the "GIS Tools" plugin to "Raster-->Reproject Grids" and setting it to "Projected-->WGS 84-->UTM Zone 14N" to see if that would help the tool recognize it, but it did not help.


Anyways, please help! Thank you :)

Even though I'm having a bit of a hiccup here, my overall impression of the tool is quite good.


(Note: I've painted over the pixel data in the Tiff itself to look like a bunch of scribbly lines on a gradient background. Don't be confused if that's what you see).

Attachments: Test_Tiff.zipx (164.3 KB)   Test_Tiff.gtf (1.6 KB)   Test_Tiff.geom (1.5 KB)   Test_Track.zip (10.6 KB)  
Options: ReplyQuote


Sorry, only registered users may post in this forum.





Banner Exchange




GISCP.com




Send us your banner logo (160x120) for the space above, and add this MapWindow banner ad to your site:

Just paste this text in your page: